Publish 'fieldbus' host taints to the ConfigDB (#15)

Define the taint `factoryplus.app.amrc.co.uk/fieldbus` to indicate 'this
host has special/limited hardware and should not be used for running
general floating workloads'. The value associated with the taint should
be a string identifying the reason for the taint being applied (these
are a matter of local policy).

If a host has such a taint, publish it to the ConfigDB. This will allow
the Manager to help users select appropriate hosts to deploy Edge Agents
to.

lib/nodes.js

@@ -16,8 +16,9 @@ import { Edge }             from "./uuids.js";
 const debug = new Debug();
 
 const LABELS = {
-    host:       "kubernetes.io/hostname",
-    control:    "node-role.kubernetes.io/control-plane",
+    host:           "kubernetes.io/hostname",
+    control:        "node-role.kubernetes.io/control-plane",
+    specialised:    "factoryplus.app.amrc.co.uk/specialised",
 };
 
 export class Nodes {
@@ -47,11 +48,16 @@ export class Nodes {
             value:      obj => {
                 const meta = obj.metadata;
                 const info = obj.status.nodeInfo;
+                const specialised = obj.spec.taints
+                    ?.filter(t => t.key == LABELS.specialised)
+                    ?.map(t => t.value)
+                    ?.[0];
                 return {
                     hostname:       meta.labels[LABELS.host],
                     arch:           info.architecture,
                     k8s_version:    info.kubeletVersion,
                     control_plane:  meta.labels[LABELS.control] == "true",
+                    specialised,
                 };
             },
             equal:      deep_equal,

package.json

@@ -1,6 +1,6 @@
 {
   "name": "acs-edge-sync",
-  "version": "0.0.2",
+  "version": "0.0.3",
   "description": "",
   "main": "index.js",
   "type": "module",